Search Results (16,753)

Despite substantial progress in medical care, acute myocarditis remains a life-threatening disorder with a sudden onset, often unexpectedly complicating a simple and common upper respiratory tract infection. In most cases, myocarditis is triggered by viral infections (over 80%), with an estimated incidence of 10–106 per 100,000 annually. The clinical course may worsen in cases of mixed etiology, where a primary viral infection is complicated by secondary bacterial pathogens, leading to prolonged inflammation and an increased risk of progression to chronic active myocarditis or dilated cardiomyopathy. We present a case report illustrating the clinical problem of acute myocarditis progression into a chronic active form. A central element of host defense is the inflammasome—an intracellular complex that activates pyroptosis and cytokine release (IL-1β, IL-18). While these processes help combat pathogens, their persistent activation may sustain inflammation and trigger heart failure and cardiac fibrosis, eventually leading to dilated cardiomyopathy. In this review, we summarize the current understanding of inflammasome pathways and their dual clinical role in myocarditis: they are essential for controlling acute infection but may become harmful when overactivated, contributing to chronic myocardial injury. Additionally, we discuss both novel and established therapeutic strategies targeting inflammatory and anti-fibrotic mechanisms, including IL-1 receptor blockers (anakinra, canakinumab), NOD-like receptor protein 3 (NLRP3) inhibitors (colchicine, MCC950, dapansutrile, INF200), NF-κB inhibitors, and angiotensin receptor-neprilysin inhibitors (ARNI), as well as microRNAs. Our aim is to emphasize the clinical importance of early identification of patients at risk of transitioning from acute to chronic inflammation, elucidate the role of inflammasomes, and present emerging therapies that may improve outcomes by balancing effective pathogen clearance with limitation of chronic cardiac damage. Full article

The escalating threat of cyanobacterial blooms necessitates a deeper understanding of the environmental factors regulating their toxicity. While light intensity effects are well-documented, it remains unclear whether photoperiod regulates microcystin (MC) production. This study investigates the effects of five light–dark (LD) cycles on the growth and MC-LR production of two Microcystis strains in batch culture under a light intensity of 25 μmol m⁻² s⁻¹. Longer photoperiods enhanced early growth, although long-term biomass accumulation proved strain-dependent. Regarding toxin production, cellular MC-LR (total toxin per cell) during the initial 9-day phase was analyzed using a mixed-effects model. The analysis revealed significant main effects of photoperiod and cell density, supporting both direct and growth-mediated indirect effects of photoperiod. Moreover, a significant strain × photoperiod × day interaction (p < 0.001) was observed, indicating additional strain-specific and time-dependent regulation. Conversely, a general linear model of the strictly intracellular MC-LR at the 27-day endpoint showed significant independent effects of photoperiod and cell density, with no interaction. The photoperiod effect strengthened after controlling for cell density. These findings reveal a phase-dependent regulation of toxicity, suggesting that risk assessment based solely on biomass is inadequate. Sustainable bloom management should therefore incorporate photoperiod dynamics and adopt phase-specific strategies. Full article

Pseudomonas aeruginosa is a versatile Gram-negative pathogen that causes various infections in humans. The bacterium possesses a type III secretion system (T3SS) to deliver cytotoxic effector proteins into host cells, which plays an important role in bacterial pathogenesis. The T3SS is regulated by the master regulator ExsA, whose expression is controlled by multiple pathways. Here, we demonstrate that the catabolite repression control protein Crc controls T3SS activity by modulating exsA expression. We find that mutation of crc reduces the intracellular cAMP level by 1.76-fold under T3SS-inducing conditions, leading to approximately 2-fold reduction of the exsA expression. Further investigation reveals that Crc affects the mRNA stability of cyaB, which encodes an adenylate cyclase involved in cAMP synthesis. The cyaB 5′-UTR is identified as a key region through which Crc affects its mRNA stability. Our study elucidates a novel regulatory mechanism by which Crc controls the T3SS through modulating cyaB mRNA stability and subsequent cAMP synthesis under T3SS-inducing conditions. Full article

Canine atopic dermatitis (cAD) is a chronic, pruritic, inflammatory skin disease with complex immunopathogenesis involving dysregulated cytokine networks. In recent years, targeted therapies have transformed the management of cAD by directly or indirectly modulating cytokine activity. Lokivetmab, a monoclonal antibody neutralizing interleukin-31, represents a breakthrough in veterinary dermatology, providing rapid and sustained reduction in pruritus with a favorable safety profile. Janus kinase inhibitors, including oclacitinib and the newer ilunocitinib, act downstream by blocking cytokine signal transduction, offering effective control of both acute and chronic phases of disease. Ciclosporin, a calcineurin inhibitor, remains a valuable immunosuppressant for long-term cAD management, while topical tacrolimus provides localized benefits. Together, these therapies mark a paradigm shift from non-specific immunosuppressants to precision medicine. In this context, precision medicine refers to therapeutic strategies that selectively target key cytokines or intracellular signaling pathways central to the pathogenesis of cAD, such as IL-31 or the JAK/STAT axis. Unlike traditional immunosuppressants such as glucocorticoids, which exert broad and non-selective immune suppression, these agents modulate defined molecular mechanisms, thereby improving efficacy and minimizing adverse effects. Consequently, they enable improved quality of life for affected dogs and their owners. Future strategies will likely focus on patient stratification and personalized approaches based on immunological endotypes. Full article

The major histocompatibility complex (MHC) class I and class II molecules (abbreviated as MHC-I and MHC-II, respectively) are specialized in antigen presentation. Unlike the T cell receptors (TCRs), which have great variability, the MHC-I and MHC-II molecules essentially have no variability at all. It is apparent that the MHC-I and MHC-II molecules per se do not have the built-in ability to distinguish the huge populations of self-peptides from antigenic non-self-peptides. At present, the precise mechanism underlying the selective presentation of antigenic peptides by both MHC-I and MHC-II molecules is unclear. For an MHC-II molecule to gain the ability to selectively present antigenic (mostly foreign) peptides, it is hypothesized herein that all naïve CD4⁺ T cells in the body will release extracellular vesicles (EVs), which are specially designed for antigen-presenting cells (APCs); these EVs contain mRNAs that will be delivered to APCs and translated into an intracellular version of the TCR proteins (iTCR^II), which will help select antigenic peptides for presentation by the MHC-II molecules. Similarly, it is hypothesized that the fully activated CD4⁺ T cells will also release EVs, and these EVs contain different mRNAs for another intracellular version of the TCR proteins (iTCR^I), which will help pathogen-infected somatic cells to select the antigenic peptides (mostly from invading pathogens) for presentation by the MHC-I molecules. Understandably, while the iTCR^II proteins will work closely with the MHC-II molecules in the exogenous endocytic pathway, the iTCR^I proteins will work closely with the MHC-I molecules in the endogenous pathway. In this paper, a few other related hypotheses are also proposed, which jointly offer a plausible mechanistic explanation for the selective presentation of antigenic peptides by both MHC-I and MHC-II molecules. While the proposed hypotheses are partly supported by some experimental observations, it is hoped that these hypotheses will promote discussion and experimental testing of the mechanisms underlying the complex process of selective antigen presentation. Full article

Salmonella Typhimurium, a significant intracellular foodborne pathogen, regulates host cell autophagy to achieve its own survival by injecting effector proteins into host cells via its type III secretion system (T3SS). Berberine hydrochloride (BH), an isoquinoline alkaloid derived from medicinal plants such as Coptis chinensis, has demonstrated potential antibacterial and immunomodulatory properties. However, the mechanisms by which BH combats S. Typhimurium by enhancing host autophagic flux through the inhibition of the type III secretion system remain to be fully elucidated. Here, we found that BH disrupts biofilm formation of S. Typhimurium, significantly inhibits the expression of genes associated with T3SS, and robustly enhances autophagy activity in macrophages infected with the pathogen. In a mouse model (C57BL/6 female 20 ± 1 g/mouse), BH significantly improved survival rates, reduced bacterial loads in tissues, and alleviated pathological damage. Molecular docking studies revealed that BH binds to key T3SS proteins, including SipB, SseA, and SsrB. These findings indicate that BH holds promise as a potentially effective therapeutic strategy for combating S. Typhimurium infections. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a sexually dimorphic condition, with higher prevalence in men than in women. Sex differences in hepatic lipid metabolism and the modulatory role of sex hormones have been described but are still insufficiently understood. The aim of this study was to introduce the variables sex and sex hormones into a human in vitro model of hepatic steatosis. Methods: Primary human hepatocytes (PHHs) were isolated from male and female donors, treated with free fatty acids (FFA) to induce steatosis, and further exposed to physiological concentrations of estrogen, progesterone, or testosterone. Intracellular triacylglyceride (TAG) content, lipid droplet (LD) formation, FFA uptake, and very-low-density lipoprotein (VLDL) excretion were assessed. In parallel, the expression of lipid metabolism-related genes was quantified by qPCR. Results: FFA treatment induced comparable uptake and intracellular TAG storage in both sexes. However, female PHHs secreted approximately twice as many VLDL particles as male cells. Steatosis significantly increased expression of LDLR, CPT2, and PLA1A only in male PHHs. Sex hormones exerted distinct, sex-specific effects: estrogen reduced TAG accumulation in female PHHs; whereas testosterone reduced TAG in male but increased it in female PHHs after prolonged treatment. LD characterization confirmed sex- and hormone-dependent differences in lipid storage patterns. In male PHHs, progesterone promoted lipid storage and increased apoB-100 secretion, accompanied by reduced LDLR and APOA5 expression, and testosterone increased the FFA-mediated CPT2 even further. Conclusions: Sex and sex hormones distinctly shape hepatocellular lipid handling under steatotic conditions. While female PHHs demonstrated greater lipid excretion capacity, male PHHs exhibited stronger transcriptional responses. Sex-specific responses to estrogen and testosterone resembled clinical observations on sex hormone effects. These findings highlight the need to account for sex-specific differences in MASLD pathophysiology and therapeutic strategies. Full article

Agaricus subrufescens Peck is a nutrient-rich edible fungi with a distinctive flavor, but most varieties are sensitive to cadmium (Cd), making cadmium contamination common during cultivation. Currently, excessive fertilizer uses and increased solid waste are exacerbating cadmium contamination in soils. Since A. subrufescens utilize agricultural residues like straw and livestock manure as cultivation substrates, Cd can be adsorbed readily, leading to secondary accumulation. In this study, the toxic effects of and response mechanisms to different Cd concentrations with respect to mycelial growth, heavy metal accumulation, and antioxidant systems of A. subrufescens were systematically investigated. The results indicated that the mycelia exhibited Cd accumulation capacity, with accumulation levels positively correlated with stress concentration. At a Cd concentration of 5 mg/L, the intracellular Cd concentration in the mycelia reached approximately 800 mg/kg. As the Cd concentration increased, the efficiency of Cd uptake by mycelia correspondingly decreased. Cadmium stress (≥0.5 mg/L) significantly inhibited mycelial growth and induced morphological abnormalities, with the mycelia exhibiting yellowing. Furthermore, Cd induced dose-dependent oxidative stress. Hydrogen peroxide and MDA levels peaked at a Cd concentration of 2 mg/L, reaching 2.26 μmol/g and 8.98 nmol/g, respectively, indicating heightened lipid peroxidation. Low concentrations of Cd (≤2 mg/L) promoted increases in ASA and GSH activity. SOD, POD, GR, and APX activities significantly increased, with the ASA-GSH cycle synergistically scavenging ROS. CAT activity remained persistently inhibited, APX/GR activity was suppressed, and total sugar metabolism was disrupted, leading to the collapse of antioxidant defenses. In summary, depending on the Cd concentration, A. subrufescens mycelia exhibit markedly different responses at low versus high concentrations. This study provides a foundation for further research into the application of edible fungi in heavy metal-resistant cultivation. Full article

Background/Objective: Dendritic cells (DCs) act as sentinels bridging innate and adaptive immunity, and their functions are strongly influenced by dietary and environmental factors. Phytochemicals such as α-Mangostin (A phytochemical, a xanthone derivative from Garcinia mangostina, known for its anti-inflammatory and antioxidant properties) are widely recognized for their antioxidant and anti-inflammatory effects, but their potential to modulate antiviral pattern recognition pathways remains unclear. This study investigated whether phytochemicals activate retinoic acid–inducible gene I (RIG-I: DDX58, a cytosolic receptor recognizing viral RNA and inducing antiviral responses)–dependent signaling in human monocyte-derived dendritic cells (MoDCs) and affect downstream T cell responses. Methods: MoDCs were generated from peripheral blood and stimulated with selected phytochemicals. RIG-I pathway–related transcripts were quantified by qPCR, and protein expression was assessed by Western blotting, intracellular flow cytometry, and immunofluorescence staining. Functional outcomes were evaluated by co-culturing MoDCs with T cells, followed by phenotypic analysis via flow cytometry and measurement of IFN-γ production by ELISA. Results: α-Mangostin stimulation increased RIG-I (DDX58) mRNA levels in MoDCs and induced time-dependent changes in intracellular protein expression. In co-culture, α-Mangostin–treated MoDCs tended to increase the proportion of OX40⁺ 4-1BB⁺ CD4⁺ T cells, accompanied by a significant elevation of IFN-γ levels in supernatants. Experiments with CpG-ODN (synthetic oligodeoxynucleotides mimicking bacterial DNA that activate TLR9) suggested context-dependent crosstalk between the TLR9 and RIG-I signaling axes. Conclusions: Phytochemicals, exemplified by α-Mangostin, prime antiviral responses in human DCs through upregulation of RIG-I and promote Th1-dependent immune responses. These findings suggest that phytochemicals may represent promising nutritional strategies to enhance antiviral immunity while mitigating excessive inflammation under infectious conditions. Full article

Paratuberculosis (Johne’s disease) is a chronic enteric infection of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP), leading to significant economic losses in livestock production. While the solute carrier family 11 member 1 (SLC11A1) gene has been implicated in resistance to intracellular pathogens in several species, its role in ovine paratuberculosis remains largely uncharacterized. The present study investigated whether polymorphic variation in the SLC11A1 3′ untranslated region (3′UTR) (GT)_n microsatellite is associated with resistance or susceptibility to MAP infection in sheep. A total of 138 sheep from three breeds (Karagouniki, Boutsika, and Chios) were genotyped. Gene expression analysis was subsequently performed on a subset of 53 animals, which comprised rigorously phenotyped MAP-resistant (n = 18) and MAP-sensitive (n = 35) individuals from the Karagouniki breed. Four predominant alleles, (GT)₂₁, (GT)₂₂, (GT)₂₃, and (GT)₂₄, were identified. The (GT)₂₁ and (GT)₂₃ alleles were significantly enriched among resistant sheep, while (GT)₂₂ and (GT)₂₄ were more frequent in sensitive animals (χ² = 12.4, p = 0.006; Cramér’s V = 0.38). No significant differences in basal SLC11A1 mRNA expression were detected between phenotypic groups. These findings extend previous GWAS results in sheep by providing the first allele-level evidence linking SLC11A1 3′UTR microsatellite polymorphisms to paratuberculosis resistance in sheep. Although limited by sample size and single-breed representation, the results offer a foundation for future functional and genomic selection studies aimed at enhancing disease resilience in small ruminants. Full article

Extracellular glutathione (GSH) is degraded on the cell surface, in which the γ-glutamyl residue is removed to generate cysteine–glycine (Cys–Gly) dipeptides that are subsequently transported to the cytoplasm. Carnosine dipeptidase 2 (CNDP2) is a cytoplasmic enzyme that hydrolyzes Cys–Gly and plays an important role in maintaining intracellular cysteine (Cys) homeostasis. CNDP2-mediated hydrolysis of Cys–Gly promotes Cys mobilization and contributes to the replenishment of intracellular GSH levels. CNDP2 is frequently overexpressed in various cancers and has been implicated in tumor cell proliferation and progression. This mechanism may enhance cancer cell survival by causing resistance to oxidative stress, which indicates that CNDP2 is a potential therapeutic target for cancer treatment. Although bestatin (BES) has been identified as a CNDP2 inhibitor, its limited specificity and suboptimal drug-like properties have limited its therapeutic potential. In this study, we performed an in silico screen of a small-molecule compound library and identified KKL-35 as a novel CNDP2-binding molecule. Molecular dynamics (MD) simulations suggested that KKL-35 interacts within the catalytic pocket. Biochemical assays confirmed that it inhibits CNDP2 enzymatic activity, albeit with lower potency compared with BES. Despite its modest intrinsic activity, KKL-35 exhibits favorable physicochemical and pharmacokinetic properties, which are characterized by a low topological polar surface area (TPSA), reduced molecular flexibility, and well-balanced lipophilicity. This positions it as an attractive and tractable starting point for lead optimization. Taken together, these findings establish KKL-35 as a validated CNDP2 inhibitor and a promising lead compound for the development of more selective therapeutics targeting CNDP2-mediated cancer cell metabolism. Full article

Endometriosis involves oestrogen-dependent chronic inflammation and the abnormal proliferation of ectopic endometrial tissue. Conventional hormonal therapies suppress systemic oestrogen, but do not fully address local oxidative and inflammatory signalling. This review provides a mechanistic synthesis of recent molecular evidence. This evidence is on four FDA-recognized (Food and Drug Administration) medicinal plants. These are Curcuma longa, Zingiber officinale, Glycyrrhiza glabra, and Silybum marianum. The review highlights their capacity to modulate key intracellular pathways. These pathways are implicated in endometriosis. The review covers the integration of phytochemical-specific actions within NF-κB- (nuclear factor kappa-light-chain-enhancer of activated B cells), COX-2-(Cyclooxygenase-2), PI3K/Akt-(PI3K/Akt signaling pathway), Nrf2/ARE-(Nuclear factor erythroid 2–related factor 2) and ERβ-(Estrogen receptor beta) mediated networks, which jointly regulate cytokine secretion, apoptosis, angiogenesis and redox balance in endometrial lesions. Curcumin downregulates COX-2 and aromatase while activating Nrf2 signalling, shogaol from ginger suppresses prostaglandin synthesis and induces caspase-dependent apoptosis, isoliquiritigenin from liquorice inhibits HMGB1-TLR4–NF-κB (High Mobility Group Box 1, Toll-like receptor 4) activation, and silymarin from milk thistle reduces IL-6 (Interleukin-6) and miR-155 (microRNA-155) expression while enhancing antioxidant capacity. Together, these phytochemicals demonstrate pharmacodynamic complementarity with hormonal agents by targeting local inflammatory and oxidative circuits rather than systemic endocrine axes. This mechanistic framework supports the rational integration of phytotherapy into endometriosis management and identifies redox-inflammatory signalling nodes as future translational targets. Full article

Cellular mechanical properties are critical indicators of cellular state and promising disease biomarkers. This study introduces a novel microhand system, featuring chopstick-like plate-shaped end-effectors, designed for stable and high-precision single-cell mechanical characterization. First, we automated the force sensor calibration to overcome the inefficiency and unreliability of conventional manual methods. To validate the system’s sensitivity, we precisely quantified the mechanical contributions of subcellular components, such as the actin cytoskeleton and chromatin, by measuring stiffness reductions after treatment with Cytochalasin D and Trichostatin A, respectively. Notably, when applied to a cellular model of Hutchinson–Gilford progeria syndrome, we successfully captured disease-induced mechanical alterations. A distinct population of high-stiffness cells was detected in progerin-overexpressing cells, a feature not observed in the control groups. Furthermore, by controlling the indentation speed and depth, the mechanical properties of the cytoplasm and nucleus could be distinctly evaluated. These results demonstrate that our microhand system is a highly sensitive and robust platform, capable of detecting subtle, disease-related changes and elucidating the contributions of specific subcellular structures to cell mechanics. Full article

Cadmium (Cd), an environmental toxin, may cause neurological disorders. We studied the role and activation mechanism of FoxO3a in Cd-induced oxidative stress. In addition to oxidative stress, Cd activated the antioxidant defense system in neuronal cells. Furthermore, by using Western blot and confocal microscopy, we found that Cd induced nuclear expression of FoxO3a. Importantly, knockdown of FoxO3a significantly suppressed its target SOD2 protein expression and elevated the level of intracellular ROS, ultimately reducing cell viability in Cd-exposed neuronal cells. These results suggest the protective effect of FoxO3a is associated with oxidative stress resistance. Then, we investigated the activation mechanism of FoxO3a. Our results indicate that the nuclear expression of FoxO3a by Cd may be independent of Akt, which is generally regarded as an important negative regulator of FoxO3a. Furthermore, we found that p38 regulated the nuclear expression of FoxO3a in Cd-exposed cells. Finally, we demonstrate that the p38-FoxO3a pathway inhibits Cd-induced oxidative stress. These signaling molecules may be used as a novel biological marker of Cd-induced oxidative stress and provide potential therapeutic approaches for it. Full article

Glioblastoma (GBM), formerly referred to as glioblastoma multiforme, represents the most prevalent and aggressive form of glioma, predominantly affecting the aging population. Despite considerable advances in recent years in elucidating its pathogenesis and developing novel immunotherapeutic approaches, the overall survival rate for patients with this central nervous system (CNS) neoplasm remains dismally low. Consequently, there is an urgent and unmet need to identify and characterize additional therapeutic targets that could be employed synergistically with existing treatment modalities to enhance both survival outcomes and quality of life. Among the emerging areas of investigation, substantial interest has been directed toward aging-associated molecular signaling mechanisms that also constitute key oncogenic pathways in GBM. These include aberrant growth factor signaling, hyperactivation of the PI3K/AKT/mTOR axis, and inactivation of critical tumor suppressor pathways such as p53 and retinoblastoma (RB). The dysregulation of these signaling cascades results in profound disturbances of essential cellular homeostatic processes, notably autophagy and cellular senescence, which are intimately involved in both tumor initiation and progression. This review aims to delineate the complex interplay between autophagy and cellular senescence within the context of aging-related GBM pathogenesis. Furthermore, it explores the relevant intracellular signaling transduction mechanisms that govern these processes and discusses prospective therapeutic strategies. Full article