Search Results (1,193)

Toll-like receptor 7 (TLR7) agonism offers a promising avenue for antiviral intervention. This study characterizes AXC-715, a novel small-molecule agonist that selectively targets TLR7 to elicit broad-spectrum antiviral effects. Structural analysis of the AXC-715–hTLR7 complex (PDB ID: 5GMH) elucidates the molecular basis of receptor activation. AXC-715 occupies the interface of TLR7 monomers, establishing critical hydrogen bonds with D555 and T586, alongside π-π and π-alkyl interactions with F408, V381, and L557. These interactions effectively promote and stabilize the active TLR7 dimeric conformation. Functionally, AXC-715 activates NF-κB signaling in a P65-dependent manner without inducing cytotoxicity in PK-15 or THP-1 cells. In vitro assays demonstrated that AXC-715 potently inhibits the replication of both pseudorabies virus (PRV) and vesicular stomatitis virus (VSV) by specifically impairing viral replication, distinct from adsorption, entry, assembly, or release processes. The antiviral effect was abolished in TLR7-knockout PK-15 cells, confirming the strict dependence of AXC-715 on on-target TLR7 signaling. These findings highlight AXC-715 as a potent TLR7 agonist that stabilizes receptor dimerization to inhibit viral replication, providing a valuable framework for developing TLR7-based antiviral therapeutics. Full article

Colorectal cancer (CRC) remains a leading cause of cancer mortality, yet no systematic effort has linked druggable CRC driver genes to downstream ion channel effectors. We integrated differential expression analysis, weighted gene co-expression network analysis (WGCNA), and protein–protein interaction (PPI) network pharmacology to identify CRC hub genes and their ion channel connections, validated by dual single-cell perturbation approaches: variational graph autoencoder-based virtual knockout (VGAE-KO) and experimental HCT116 CRISPRi Perturb-seq (6 genes, 8445 cells). WGCNA identified 100 hub genes spanning three functional programs. Ribosomal proteins link to K${}^{+}$ channels (RPS21→KCNQ2, targetable by EMA-approved ataluren, passed dual validation at 97.8th–98.7th percentile). RNA processing genes connect to Cl${}^{-}$ channels (LSM7→CLIC1, strongest signal at 99.8th–99.4th percentile). Immune checkpoint receptors (LAG3, CD27) connect via PPI intermediates to Ca${}^{2+}$ and K${}^{+}$ channels, targetable by relatlimab (FDA-approved) and varlilumab (Phase 2). This work maps previously unknown links between CRC driver genes and ion channel regulation, with the ataluren-RPS21-KCNQ2 axis ready for pharmacological testing. Full article

Background/Objectives: Amelogenesis imperfecta (AI) is a heterogeneous group of rare hereditary conditions mainly affecting the quantity and/or quality of tooth enamel. Its phenotypic expression is diverse, as is the mutational spectrum of the AI-causing genes and mutations. Integrins are cell-surface receptors that mediate adhesion between cells and between cells and the extracellular matrix. Among these, mutations in integrin αvβ6 have been shown to cause AI; however, phenotypic variation exists between the knockout mouse model and human cases, as well as among different human AI families. Methods: We recruited AI families and performed mutational analysis using whole exome sequencing. Results: We identified compound heterozygous ITGB6 mutations in two families. In Family 1, a paternally transmitted nonsense mutation (NM_000888.5: c.1060C>T, p.(Gln354*)) and a maternally transmitted missense mutation (NM_000888.5: c.2312A>G, p.(Asn771Ser)) were identified; in Family 2, a paternal missense mutation (NM_000888.5: c.1693T>C, p.(Cys565Arg)) and a maternal frameshift mutation (NM_000888.5: c.2091delC, p.(Asn698Metfs*13)) were identified, each causing AI in the respective proband. Both probands exhibited generalized hypoplastic and hypomineralized AI, but no other extraoral symptoms. Conclusions: This report will not only expand the known mutational spectrum of the ITGB6 gene but also provide evidence for the genotype–phenotype correlations, thereby improving our understanding of the functional role of ITGB6 during amelogenesis. Full article

Background: Spinal cord injury (SCI) is a severe pathological condition resulting in persistent motor and sensory impairments. The trace amine-associated receptor 5 (TAAR5) is a potential modulator of central nervous system functions; however, its role in CNS repair remains poorly understood. Methods: We comprehensively evaluated the effect of TAAR5 gene knockout on functional recovery following lateral spinal cord hemisection in TAAR5-KO and wild-type (WT) male mice. Sensorimotor recovery after SCI was assessed using the horizontal ladder, grasp, and hindlimb mobility tests. Exploratory and anxiety-like behaviors were evaluated using the open field and elevated plus maze tests before and 5 weeks after SCI. Results: TAAR5-KO mice exhibited accelerated recovery of sensorimotor functions, as assessed by joint mobility and grasping tests, compared to WT animals. In contrast, no significant intergroup differences were found in the Horizontal Regular Ladder test, likely due to the task complexity and an insufficient recovery period. Nevertheless, SCI induced elevated anxiety-like behavior regardless of genotype. Conclusions: These findings indicate that TAAR5 deficiency exerts a positive modulatory effect on the restoration of specific components of sensorimotor function after SCI. This effect may be mediated through the modulation of dopaminergic neurotransmission and inflammatory processes. The observed beneficial effect of TAAR5 knockout identifies this receptor as a promising target for developing novel therapeutic strategies aimed at improving functional outcomes following spinal cord injury. Full article

Malaria, caused by Plasmodium parasites, remains a global health crisis, necessitating novel therapeutic strategies targeting host–parasite interactions. During liver-stage infection, parasites exploit host vesicular trafficking machinery, particularly SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins that mediate membrane fusion. Using a CRISPR/Cas9 knockout system in HeLa cells combined with advanced microscopy of Plasmodium berghei-infected HeLa cells, we identified specific endolysosomal SNAREs including Vesicle-Associated Membrane Protein 7 (VAMP7), Vesicle-Associated Membrane Protein 8 (VAMP8), Vesicle Transport Through Interaction With T-SNAREs 1B (Vti1B), and Syntaxin 7 (Stx7) to be recruited to the parasitophorous vacuole membrane (PVM) with distinct temporal profiles. This demonstrates the parasite’s precise manipulation of host endolysosomal trafficking pathways. VAMP7 and Vti1B were localized to the PVM within 30 min post-infection, suggesting potential roles during invasion, while VAMP8 and Stx7 appeared later around 24 h post infection (hpi), coinciding with increased nutrient acquisition. Single gene deletions showed minimal impact, but combinatorial knockouts (KO) revealed critical redundancy. VAMP7-VAMP8 as well as VAMP7–Vti1B double KO significantly reduced parasite infection and growth, with Vti1B playing a dominant role. Triple KO phenotypes mirrored VAMP7-Vti1B disruption, underscoring Vti1B’s dominant role. SNARE depletion also impaired the lysosome–PVM association and LAMP1 positive vesicle recruitment. Our findings indicate Plasmodium hijacks a coordinated host SNARE network to fuse lysosomes with the PVM for nutrient uptake. Targeting Vti1B-containing complexes disrupts this pathway without host cell toxicity, offering a promising host-directed antimalarial approach. Full article

Respiratory syncytial virus (RSV), a member of the genus Orthopneumovirus, is an etiological agent in infant lower respiratory tract infections (LRTIs) producing substantial global morbidity. Here, secretoglobin (Scgb1a1)-derived progenitors play a primary role in triggering innate, inflammatory, and cell state transitions in response to RSV LRTIs. Whether RSV activation of innate signaling in this epithelial sentinel population leads to chronic airway disease is unknown. To understand the role of innate signaling in Scgb1a1-derived progenitors, a model of RSV post-viral disease (PVLD) was developed and studied in the presence or absence of RelA conditional knockout (CKO). Single-cell RNA sequencing (scRNA-seq) studies showed that RSV-PVLD induced a transition of atypical, differentiation-intermediate, alveolar type 2 (aAT2) cells characterized by tumor protein 63 (TRP63), aquaporin 3 (AQP3), and Itgβ4 expression, as well as changes in PDGFRβ mesenchyme. A single-cell trajectory analysis and lineage-tracing experiments using Scgb1a1 CreER^TM X mTmG mice demonstrated that the Scgb1a1+ populations were precursors to the aAT2 population. Mechanistically, we found that the formation of the aAT2 population was prevented by RelA CKO. A differential gene expression analysis revealed that RSV-PVLD coordinately upregulates nuclear receptor subfamily 1 group D (Nr1d1/2), clock and basic helix-loop-helix ARNT-like 1 (Bmal) genes both in the aAT2 cell and in its Pdgfrα+ mesenchymal niche in a RelA-dependent manner. A systematic analysis of intercellular epithelial–mesenchymal communication in the scRNA-seq data showed that the clock-dysregulated epithelial–mesenchymal niche produces aberrant ANGPTL4 expression. ANGPTL4 upregulation was confirmed by the measurement of both its mRNA and protein. Moreover, ANGPTL4 is biologically active in the BALF of RSV-PVLD mice, inhibiting lipoprotein lipase activity. We conclude that RSV-PVLD is mediated, at least in part, by RelA signaling in Scgb1a1-derived epithelial progenitors, dysregulating ANGPTL4 signaling in an epithelial–mesenchymal niche, resulting in persistence of atypical alveolar epithelial cells with dysregulated of clock gene expression. Full article

Sex differences remain largely underexplored in metabolic disorders, particularly in the context of genetic predisposition to type 2 diabetes, the impact of aging, and environmental factors such as exposure to high-caloric diets. Previous studies using serotonin transporter (SERT)-knockout (SERT-KO) mice, which recapitulate metabolic conditions related to the lowered function of this transporter in humans, revealed an aggravated negative response of these mutants to housing on a high-fat/sugar ‘Western diet’ (WD). However, the role of sex in SERT-KO mice has not yet been studied. Available human and animal data suggest the differential regulation of insulin receptor-mediated signaling in males and females, which can be altered with aging. This study aimed to compare fat accumulation, blood biochemical changes, glucose tolerance, and insulin receptor (IR)-related signaling in the liver and various brain structures of 12-month-old male and female SERT-KO mice fed WD for 21 days. Relative to the dietary-unchallenged group and their wild-type (WT) littermates, WD-fed mutants of both sexes displayed markedly increased fat accumulation and impaired glucose and insulin tolerance. Body mass increase was more prominent in females than in males. The two sexes revealed a similar suppression of the gene expression of isoforms A and B of IR but distinct expression of IR-related factors. IR-related genes such as Cd36, Enpp, Ptpn1, Cyp4a14, Acsl1, and Pten showed differential expression between male and female SERT-KO mice fed WD. Several differences in gene expression were also found between the WT groups of the two sexes. Overall, the manifestations of hepatic steatosis, insulin resistance, and glucose tolerance were similar between the age groups of animals, whereas the gene expression of IR-related regulation differed between the groups. We conclude that aging and genetic absence of the serotonin transporter likely override sex differences in the end effects of WD challenge, while molecular mechanisms of adaptation of IR-mediated signaling are distinct between male and female SERT-KO mice fed WD. Full article

Skin fibrosis is characterized by excessive extracellular matrix (ECM) deposition, leading to tissue dysfunction and scarring. Transforming growth factor (TGF)-β is a central mediator of fibrosis. We previously identified CD109 as a TGF-β co-receptor and negative regulator of TGF-β signaling and fibrotic responses and showed that its epidermal overexpression reduces dermal fibrosis in vivo. However, the effects of CD109 loss in the dermis remain unclear. The current study investigates the impact of CD109 knockout (KO) on skin fibrosis using a bleomycin-induced fibrosis mouse model. Following bleomycin treatment, CD109 KO mice showed increased collagen I deposition and elevated fibronectin, CCN2, and α–smooth muscle actin expression in the skin, indicating enhanced ECM production and myofibroblast differentiation compared with wild-type mice. Additionally, CD109 KO mice displayed enhanced Smad1 and Smad2/3 phosphorylation in the skin, indicating heightened TGF-β signaling. In vitro, CD109 KO fibroblasts exhibited increased TGF-β-induced migration and collagen contraction. These findings suggest that CD109 deficiency exacerbates dermal fibrosis by promoting TGF-β/Smad signaling and myofibroblast activation. Given its dysregulation in fibrotic disorders such as scleroderma, our results identify CD109 as a key regulator of skin homeostasis by modulating ECM production and fibroblast activation, underscoring its potential as a therapeutic target in fibrotic disorders. Full article

CDKL5 Deficiency Disorder (CDD) is a severe neurodevelopmental encephalopathy characterized by early disruptions of synaptic maturation and network stability, leading to persistent motor, cognitive, and behavioral impairments. Given the role of the endocannabinoid system in synaptic development, neuroinflammation, and neuronal resilience, we investigated whether the sustained enhancement of endogenous 2-arachidonoylglycerol (2-AG) signaling via monoacylglycerol lipase (MAGL) inhibition could mitigate key pathological features in adult Cdkl5 knockout (KO) mice. Using an intermittent 6-week treatment, the MAGL inhibitor JZL184 robustly increased plasma 2-AG levels, reduced MAGL protein levels, and activated CB1-AKT signaling without evidence of receptor desensitization. Despite this clear pharmacodynamic efficacy, behavioral effects were domain-specific: neither dose ameliorated core behavioral deficits, although the higher dose selectively reduced stereotypic jumping and modestly improved cue-dependent associative memory. At the cellular level, JZL184 induced biologically meaningful effects, partially restoring dendritic spine maturation in the primary somatosensory cortex and increasing neuronal survival in the vulnerable CA1 hippocampal region. In contrast, microglial responses were dose-dependent and divergent, with the lower dose exerting anti-inflammatory effects, while the higher dose increased cortical microglial density and Allograft Inflammatory Factor-1 (AIF-1) expression, suggesting engagement of compensatory or off-target mechanisms. Overall, these findings show that MAGL inhibition activates neuroprotective pathways and ameliorates select structural deficits in adult Cdkl5 KO mice, but is insufficient to produce broad behavioral recovery, highlighting the domain-specific effects of selective 2-AG enhancement via MAGL inhibition and the need for developmentally informed or multimodal therapeutic strategies in CDD. Full article

Patients with nephronophthisis caused by nephrocystin 3 (NPHP3) variants rapidly progress to end-stage kidney disease. However, existing Nphp3 mouse models fail to fully recapitulate the characteristics of this disease. We generated a renal tubule-specific Nphp3 knockout mouse model that more accurately mirrors the human disease course. The mouse model was first validated by confirming the loss of Nphp3 protein expression in renal tubules. Comprehensive phenotypic analyses were then performed to assess both renal and extrarenal manifestations. The origin of renal cysts was investigated, and the underlying mechanisms were further validated. We successfully generated a renal tubule-specific Nphp3 knockout mouse model (Cdh16-Cre; Nphp3^flox/flox). These mice exhibited a markedly shortened lifespan (5–8 weeks) and developed key features of infantile nephronophthisis, including early-onset renal cysts originating from distal tubules and collecting ducts, progressive interstitial fibrosis that was evident by postnatal week 2, a rapid decline in kidney function, and increased urinary protein levels. Importantly, treatment with the vasopressin V2 receptor antagonist tolvaptan or the mitogen-activated extracellular signal-regulated kinase (MEK) inhibitor 2-(2-chloro-4-iodoanilino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide (CI-1040) significantly attenuated cyst growth and improved kidney morphology, confirming shared pathogenic pathways with other Nphp3 models. We established a renal tubule-specific Nphp3 knockout mouse model that accurately recapitulates the aggressive infantile form of nephronophthisis characterized by early cystogenesis, progressive fibrosis, and a shortened lifespan, and is ideal for evaluating novel interventions against this currently untreatable ciliopathy. Full article

Background/Objectives: Humans have at least 26 bitter taste receptors (T2Rs), and among these, bitter taste receptor 14 (T2R14) is highly expressed in both oral and extraoral tissues. Over 100 bitter ligands can activate T2R14, including hormones, vitamins, plant compounds, and peptides. Previous studies suggest that bitter tastants such as quinine and caffeine can inhibit G protein-coupled receptor kinases (GRKs) and delay T2R signal termination. Our earlier research showed that peptides from alcalase and chymotrypsin hydrolysates of beef proteins inhibited quinine-dependent calcium release through T2R4, with AGDDAPRAVF and ETSARHL showing the greatest effectiveness. However, the effect of these antagonistic peptides on other T2Rs, such as T2R14 signaling, remains unknown. This study aimed to evaluate the ability of these beef protein-derived peptides to activate or inhibit T2R14 signaling and the involvement of GRK2 in signal termination. Methods and Results: Our results indicate that the above two antagonist peptides significantly inhibit T2R14 activity. Furthermore, GRK2 knockout in HEK cells stably expressing T2R14 decreases intracellular calcium release, as measured by the area under the curve (AUC), and also delays the fall time (indication of desensitization) of the calcium response when exposed to the T2R14 agonist diphenhydramine (DPH) or beef protein-derived agonist peptide TMTL. Next, we measured the effects of these ligands on cAMP accumulation, and our results suggest no significant change in cAMP levels upon treatment with beef protein-derived peptides. Conclusions: Thus, this study showed that beef protein-derived peptides can function as both T2R inhibitors and mediate T2R14 desensitization through GRK2 signaling. These antagonistic food protein-derived peptides inform strategies to enhance nutrition, such as promoting healthier food choices by reducing bitterness and thereby improving the palatability of health-promoting bitter foods, such as fruit and vegetable extracts, as well as bitter medications. Full article

Colorectal cancer (CRC) is a prevalent malignant tumour, with its incidence and mortality rates consistently ranking among the highest and exhibiting an upward trend. Extensive screening and early diagnosis are crucial for managing CRC progression and improving patient prognosis. This study aims to construct a novel analytical framework for integrating the sequencing data from tumour tissue and peripheral blood. By integrating and analysing the multi-omics data and clinical data from tumour tissues and peripheral blood, we confirmed that the LTB4R gene is significantly upregulated not only in tumour tissues but also in the peripheral blood of CRC patients. Further single-cell RNA sequencing (scRNA-seq) and immune cell correlation analyses revealed that Leukotriene B4 receptor 1 (LTB4R) is primarily expressed in macrophages, T cells, and other immune cells, with a significant negative correlation observed with M1-type macrophages, suggesting its potential pro-tumourigenic role in CRC by suppressing M1 macrophage. Additionally, simulated gene knockout analysis (scTenifoldKnk) demonstrated that LTB4R knockout significantly impacts immune-related pathways, including immune response and immune receptor activity. These findings not only highlight the potential of LTB4R as a peripheral blood diagnostic marker for CRC but also elucidate its involvement in tumour progression, offering novel insights for early clinical diagnosis and tumour screening systems. Full article

The intestinal barrier undergoes profound changes with age, impacting local immunity and systemic health, yet the mechanisms coordinating immune and microbial dynamics across the lifespan remain incompletely understood. Toll-like receptor 4 (TLR4) serves as a key mediator of host–microbiota interactions. This study investigated age-related changes in barrier function and the role of TLR4 using C57BL/6J and TLR4 knockout (TLR4^−/−) mice across key developmental stages: pups (postnatal day 9), adults (2–4 months), middle-aged (7–9 months), and old (16–19 months). Through a multi-layered approach integrating histology, microbiome profiling, short-chain fatty acid (SCFA) analysis, cytokine quantification, ex vivo functional assays, and transcriptomics, we identified a multi-phase process of intestinal remodeling. Pup-P9 mice exhibited immature colonic structure, a simple microbiota dominated by Firmicutes and Proteobacteria, and undetectable acetic acid level. Adults reached peak diversity and SCFA concentrations, marked by a rise in Bacteroidota and the emergence of Akkermansia. In middle and old age, pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) increased, Bacteroidota declined while Firmicutes, Actinobacteria, and Turicibacter expanded, and aged colons showed blunted ex vivo responses to IL-1β. This age-associated functional decline phenotype was absent in TLR4^−/− mice, supporting the involvement of TLR4 signaling. Transcriptomics further revealed biphasic PI3K/Akt activation in both pups-P9 and old mice. Together, these findings suggest a systemic rewiring of host metabolic and immune signaling pathways in response to an aging microbiota, highlighting this dynamic, lifespan-wide microbiota–host signaling axis as a potential intervention target. Full article

To explore the mechanism of action of CBS-derived H₂S in inducing cerebral vasodilation and activating BK_Ca channels. Sprague–Dawley (SD) rat middle cerebral arteries (MCA) were isolated from rat brains, and a pressure myography system was used to measure the effects of different concentrations of L-cysteine (L-Cys, 1 × 10^−5.5 to 1 × 10^−3.5 mol/L), a substrate for cystathionine-β-synthase (CBS)—a hydrogen sulfide (H₂S)-producing enzyme. Additionally, the effects of pretreatment with the CBS inhibitor amino-oxoacetate (AOAA, 1 mmol/L), the vascular endothelial growth factor receptor 2 inhibitor semaxanib (SU5416, 10 μmol/L), and the large-conductance calcium-activated potassium (BK_Ca) channel blocker iberiotoxin (IBTX, 100 nmol/L) were investigated to determine their impacts on CBS-derived H₂S-induced vasodilation. Acute digestion of rat vascular smooth muscle cells (VSMCs) was performed, and whole-cell patch-clamp techniques were used to measure current changes in neurons or astrocytes (ASTs), as well as acutely digested VSMCs, in the presence of L-Cys, AOAA (1 mmol/L), SU5416 (10 μmol/L), and IBTX (100 nmol/L). Additionally, neurons or ASTs were co-cultured with VSMCs to determine CBS-derived H₂S levels. Neurons or ASTs co-incubated with blood vessels and then treated with L-Cys produced H₂S, which exhibited a concentration-dependent dilatory effect on middle cerebral artery occlusion (MCA) pre-contracted with 100 nmol/L U46619 (p < 0.01). However, the addition of AOAA significantly attenuated this dilatory effect (p < 0.01). SU5416 and IBTX significantly inhibited cerebral vascular dilation (p < 0.01). H₂S produced by adding L-Cys after co-incubation of neurons or ASTs with VSMCs significantly increased BK_Ca channel current (p < 0.01). However, this effect was significantly attenuated after adding AOAA (p < 0.01). SU5416 and IBTX significantly inhibited the activation of BK_Ca channels (p < 0.01). Wild-type rat neurons or astrocytes (ASTs) were co-cultured with CSE(Cystathionine γ-lyase)-knockout vascular smooth muscle cells (VSMCs-CSE KO); the addition of L-Cys significantly increased hydrogen sulfide (H₂S) levels in the co-culture system (p < 0.01), while the addition of AOAA reduced H₂S production (p < 0.01). However, the addition of SU5416 had no statistical significance. Neurogenic H₂S, the H₂S produced by neurons and ASTs, could induce cerebral vasodilation in rats via VEGFR₂(Vascular Endothelial Growth Factor Receptor 2)-mediated activation of BK_Ca channels in the smooth muscle cells. Full article

Background: Fibromyalgia is a chronic disease that predominantly affects women and lasts over several months, causing problems both for individuals and society. While several studies have demonstrated the potential of electroacupuncture (EA) to alleviate fibromyalgia pain in mice, further research is needed to investigate its underlying mechanisms. Programmed cell death ligand 1 (PD-L1)/PD-1 were first identified to be involved in cancer immunotherapy, and their application to pain management has not been yet investigated. Methods: In this study, we aimed to explore the mechanism underlying the action of PD-L1 on the PD-1 pathway in a mouse model of fibromyalgia. Results: We established such a mouse model using intermittent cold stress (ICS) and confirmed mechanical (D4: 2.02 ± 0.13 g, n = 9) and thermal (D4: 4.28 ± 0.21 s, n = 9) hyperalgesia. We found that EA, intracerebral ventricle (ICV) PD-L1 injection, and transient receptor potential vanilloid 1 (Trpv1) knockout effectively counteracted hyperalgesia. We observed low PD-1 expression in the cerebellum of fibromyalgia mice but increased expression of TRPV1 and pain-related kinases. These phenomena could be further reversed by EA, ICV PD-L1 injection, and Trpv1 knockout. To confirm that these effects were caused by PD-L1 release, we added PD-L1-neutralizing antibodies to the EA and PD-L1 treatment. The analgesic effects and EA and PD-L1 mechanisms were inhibited. Conclusions: Our results elucidate the role of the PD-L1/PD-1 pathway in EA treatment of fibromyalgia and reveal its potential value for fibromyalgia management. Full article