Search Results (999)

Ulcerative colitis (UC) is a chronic, relapsing inflammatory bowel disease characterized by mucosal inflammation and epithelial barrier disruption. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, the principal cytosolic DNA-sensing axis, has emerged as a critical node in UC pathogenesis. This review elucidates the cGAS/STING signaling network in UC, from its upstream activation triggered by exogenous stimuli and leaked endogenous DNA to its downstream effects. We discuss how this pathway modulates distinct lines of intestinal defense, including the mechanical, chemical, and immunological barriers, while integrating its bidirectional crosstalk with the microbial barrier. Rather than exerting purely detrimental effects, cGAS/STING functions as a double-edged sword that coordinates both barrier homeostasis and inflammatory pathogenesis. Crucially, we summarize current pharmacological interventions, highlighting synthetic small molecules and bioactive natural products that target and modulate this axis to restore intestinal equilibrium. This framework provides a theoretical foundation for future precision therapies in UC. Full article

Antisense oligonucleotides (ASOs) are short, synthetic DNA fragments able to modulate gene expression. In this work, the cytosolic isoform of glucose-6-phosphate dehydrogenase (Cyt-G6PDH) was selected as a target for ASOs to induce transient gene silencing in barley (Hordeum vulgare). G6PDH is the most important enzyme of the oxidative pentose phosphate pathway (OPPP), supplying NADPH and regulating the entire cycle. Different ASOs were tested at different concentrations on the leaf surface. Their effects were evaluated by measuring enzymatic activity, gene expression, and protein abundance. Treatment with 30 µM ASOs for 6 h represented the optimal condition, inducing a 40–60% reduction in G6PDH total activity in barley leaves, with a specific decrease in the cytosolic isoform, as determined by DTT-sensitive enzymatic assays. ASOs designed on the main regulator of cyt-G6PDH, the shaggy-like kinase (SK11), led to an analogous effect in terms of G6PDH activity, confirming the involvement of HvSK11 in the regulation of cyt-G6PDH in barley. Consistently, qRT-PCR analyses showed that ASO treatment simulates an abiotic stress condition obtained by the down-regulation of Cyt-G6PDH. These results support the use of ASOs as a rapid and efficient method for the functional analysis of key metabolic regulators in plants to overcome complications in recalcitrant organisms or lethal genes. Full article

Introduction: Sevoflurane may exert cytotoxic effects in some cell types, but its impact on human cardiomyocytes and the potential protective role of remifentanil remain unclear. This study aimed to investigate whether remifentanil mitigates sevoflurane-induced apoptotic damage in human cardiomyocytes, with an exploratory focus on TRPA1 calcium channels. Materials and Methods: Human cardiomyocyte cells were exposed to sevoflurane (5.1% for 6 h) and/or remifentanil (2.5 µM for 30 min), with or without the TRPA1 antagonist AP18. Apoptosis, intracellular reactive oxygen species (ROS), mitochondrial depolarisation, caspase-3 and -9 activities, and cytosolic calcium levels were measured. Results: Sevoflurane exposure was associated with increased apoptosis, ROS production, mitochondrial depolarisation, caspase-3 and -9 activities, and intracellular calcium levels compared with the control group. Remifentanil pretreatment appeared to reduce these sevoflurane-related changes. In several parameters, the addition of AP18 partially reversed the effects of remifentanil, suggesting that TRPA1 channels may contribute to these effects. However, findings were not entirely consistent across all measured variables. Conclusions: Remifentanil effectively mitigates sevoflurane-induced apoptotic damage in human cardiomyocytes, likely by modulating oxidative stress and preserving mitochondrial function. The partial reversal by AP18 suggests that TRPA1 channels may contribute to these protective effects, though additional mechanisms are likely involved. Further mechanistic and translational studies are warranted to elucidate the precise signalling pathways and clinical relevance of these observations. Full article

Background/Objectives: Cryptosporidiosis, caused by Cryptosporidium parvum, is a significant cause of diarrheal disease, particularly affecting young children and immunocompromised individuals. With current treatments offering limited efficacy, there is an urgent need for novel therapeutic targets. Methods: In this study, we report the cloning, expression, and functional characterization of a glutathione transferase (GST) from C. parvum (CpGST). Results: Biocomputing analysis revealed a single gene encoding a cytosolic enzyme with distinct structural features, compared to human cytosolic homologs. Structural modeling indicated a non-canonical thioredoxin fold and a truncated C-terminal domain, suggesting functional divergence. CpGST was expressed in Escherichia coli, and its enzymatic properties were characterized. Although the enzyme displayed a narrow substrate spectrum, it showed a distinct substrate preference, retaining catalytic activity toward the standard GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and cumene hydroperoxide (CuOOH). Steady-state kinetic analysis revealed limited affinity for both reduced glutathione (GSH) and CDNB. Inhibition analysis identified several polyphenols and synthetic curcumin analogues as potent inhibitors, with IC₅₀ values in the low micromolar range. Kinetic analysis with the most potent inhibitor revealed a mixed-type inhibition mechanism. Conclusions: These findings support the classification of CpGST as a structurally and functionally distinct member of the GST family, likely adapted to the parasite’s physiology and metabolism. The enzyme’s divergence from human GSTs, along with its favorable druggability profile, underscores its potential as a target for anti-cryptosporidial drug development, particularly in strategies aimed at disrupting stress response and detoxification pathways. Full article

Pyruvate kinase (PK) is the terminal rate-limiting enzyme of glycolysis and occupies a central position in plant energy metabolism and carbon skeleton allocation. Plant PK isoenzymes comprise the cytosolic pyruvate kinase (PKc) and the plastidic pyruvate kinase (PKp), which differ markedly in gene origin, protein structure, subcellular localization, and physiological function, exhibiting independent evolutionary histories and functional diversification. Recent studies have revealed that PKc possesses dynamic subcellular distribution, allowing it to shuttle among the cytosol, mitochondria, and nucleus, where it participates in stress responses and epigenetic regulation through protein–protein interactions. PKp is localized to plastids and connects carbon metabolism with lipid biosynthesis and the methylerythritol phosphate (MEP) pathway by supplying pyruvate, thereby playing critical roles in seed development and oil accumulation. This review comprehensively summarizes recent advances in plant PKc and PKp concerning protein structure and subunit composition, tissue-specific expression, subcellular localization, protein interaction networks, activity regulation, and their effects on plant growth, development, and stress responses. In addition, phylogenetic tree, motif, and domain analyses of pyruvate kinase genes from Oryza sativa (rice), Glycine max (soybean), Gossypium hirsutum (cotton), Solanum tuberosum (potato), Arachis hypogaea (peanut), and Arabidopsis thaliana, as well as promoter cis-element analyses, are performed. This review aims to provide theoretical references for crop quality improvement and stress-resilient breeding. Full article

The Warburg effect is better understood as regulated metabolic plasticity rather than mitochondrial failure. Many malignant cells retain functional mitochondria while increasing aerobic glycolysis, lactate production, and redox remodeling to support growth, immune escape, and adaptation to microenvironmental stress. Within the context of the cancer microenvironment, this review examines xylitol as a hypothetical metabolic modifier within a broader host-microbe-mitochondria framework. Xylitol, a five-carbon sugar alcohol, is derived endogenously through the pentose phosphate pathway (PPP) and the glucuronate–xylulose pathway, and is metabolized efficiently in humans, rats, and pigs through xylitol dehydrogenase (XDH) in hepatic mitochondria and the cytosol; whereas, it is less tolerated by obligate carnivores who lack this enzyme. Preclinical studies show that partial substitution of glucose with xylitol can reduce proliferation and glycolytic markers in oral squamous carcinoma models, and preliminary studies link xylitol to glutathione depletion, endoplasmic reticulum (ER) stress, autophagy-associated death, and altered tumor metabolomics. On the other hand, oral pathogens such as Fusobacterium nucleatum and Porphyromonas gingivalis promote tumor stemness, extracellular vesicle signaling, metastasis, and immune evasion. In addition, Streptococcus mutans, the primary cariogenic pathogen, contributes to systemic bacteremia and epithelial–mesenchymal transition. Oral and gut microbiomes modulate macrophage polarization, T cell activity, and the senescence-associated secretory phenotype (SASP), possibly promoting cancer immune evasion. The anti-adhesive properties of xylitol may limit pathogen attachment to immune cell receptors, reducing the generation of pro-tumorigenic senescent immune cells. Xylitol also offers metabolic benefits, a low glycemic index, partial insulin-independent metabolism, and potential diabetes-prevention activity that are relevant, considering the established link between metabolic disease and cancer risk. A recent study reported that higher levels of endogenous xylitol were associated with adverse cardiovascular events, but confirmation of this requires large scale prospective studies. The evolutionary dietary context of MIS 6, during which hominin populations in sub-Saharan Africa depended on polyol-rich underground storage organs, provides a biological basis for human tolerance of xylitol. As a result, we hypothesize that xylitol may be a context-dependent metabolic modifier within an integrated host–microbe–mitochondria–cancer stem cell network. Full article

Salmonella is a globally significant foodborne intracellular pathogen, and invasive salmonellosis poses a major global public health threat. The NLR family CARD-containing protein 4 (NLRC4) inflammasome, a pivotal cytosolic innate immune sensor, specifically recognizes Salmonella flagellin and type III secretion system (T3SS) components via the NAIP (NLR family apoptosis inhibitory protein) family. Upon activation, it triggers pyroptosis, pro-inflammatory cytokine release, and infected intestinal epithelial cell extrusion, serving as a central pathway for host defense against Salmonella colonization and systemic spread. This work systematically summarizes the structural composition, activation mechanisms, post-translational modifications, and regulatory protein network of the NLRC4 inflammasome, and highlights the molecular mechanisms by which Salmonella evades NLRC4 surveillance through multiple strategies: transcriptional downregulation of immunogenic ligands, structural modification of T3SS components, secretion of effector proteins, and chemotaxis-virulence synergy. A comprehensive delineation of the co-evolutionary arms race between Salmonella and the NLRC4 inflammasome provides an integrated mechanistic framework for understanding host–pathogen immune interplay. Deciphering the mechanisms of bacterial immune evasion on this basis holds critical importance for identifying novel anti-infective targets and advancing translational preventive and therapeutic strategies against salmonellosis. Full article

Background/Objectives: Gamma-aminobutyric acid (GABA) is increasingly recognized as an important modulator of pancreatic beta-cell function, but the mechanisms by which it regulates intracellular Ca²⁺ oscillations and coordinated beta-cell activity remain insufficiently understood. The aim of this study was to investigate how GABA influences the amplitude, frequency, phase adjustment, entrainment, and synchronization of beta-cell Ca²⁺ oscillations. Methods: We developed a reduced ATP–Ca²⁺ oscillation model, based on established beta-cell oscillatory frameworks, and coupled it to the GABA-shunt subsystem derived from our previously established Dual Anaplerotic Model. The model incorporates explicit dynamics of cytosolic Ca²⁺, endoplasmic reticulum Ca²⁺, ATP, and a regulatory variable controlling Ca²⁺ influx, while the interstitial GABA signal is represented as a delayed feedback signal acting on cellular excitability. Single-cell and two-cell simulations were performed to analyze GABA-dependent oscillatory regulation and intercellular coupling. Results: The model reproduced key experimental observations under both control and GABA-deficient conditions, including reduced Ca²⁺-oscillation amplitude and a prolonged oscillation period when GABA production was suppressed. Mechanistically, GABA affected single-cell oscillations through two complementary pathways: metabolically, by modulating ATP production through PEP-related and TCA-related contributions linked to the GABA shunt, and as an interstitial/paracrine signal, by adjusting the phase of Ca²⁺ influx through fast and delayed inhibitory feedback. In the reduced two-cell model, delayed interstitial GABA signaling could phase-lock non-identical oscillators over finite ranges of parameter mismatch. When included as an additional weak effective term, electrical coupling broadened these ranges, consistent with a complementary interaction between GABA-mediated phase adjustment and established electrical coupling. Conclusions: GABA acts as a dual regulator of beta-cell dynamics, linking intracellular metabolism to Ca²⁺-oscillation patterning and promoting coordinated activity through intercellular phase adjustment. The model provides a mechanistic framework connecting GABA metabolism, ATP dynamics, Ca²⁺ signaling, and beta-cell synchronization in pancreatic islets. Full article

Virus infection requires coordinated activation of pathogen-sensing, innate immune, and cellular stress response pathways to mount an effective antiviral defense. Recognition of nucleic acid pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) initiates signaling cascades that drive the production of type I interferons (IFNs) and proinflammatory cytokines. These responses are often accompanied by the activation of integrated stress response pathways that help optimize host defense. Cytosolic double-stranded dsDNA, generated during viral infection or released from damaged mitochondria, is sensed by cyclic GMP-AMP synthase (cGAS), which generates 2′3′-cGAMP to activate stimulator of interferon genes (STING). Activated STING translocates from the endoplasmic reticulum to the Golgi, where it drives TBK1-dependent IFN and cytokine production. Previous reports show that cGAS activity is enhanced by Ras-GAP SH3 domain binding protein 1 (G3BP1), a key nucleator of stress granules (SGs), independent of its role in SG assembly. Here, we identify a non-canonical role of G3BP1 as a regulator of DNA sensing responses at multiple levels, including STING intracellular trafficking, in addition to potentiating cGAS activity. Loss of G3BP1 impaired STING-dependent IFN and cytokine responses to HSV-1 infection and viral DNA. G3BP1-deficient cells showed reduced cGAMP-induced STING translocation to the Golgi, induction of type I IFN and proinflammatory cytokines, and activation of the ER stress kinase PERK and stress granule formation. Together, these findings demonstrate G3BP1-STING as a node linking DNA sensing, innate immunity, and stress signaling with broad implications for antiviral defense and diseases characterized by aberrant DNA sensing and stress responses, including neurodegeneration, fibrosis, and autoimmunity. Full article

Palmatine chloride (berbericinine, C₂₁H₂₂ClNO₄) is a protoberberine alkaloid found in several plants, including Rhizoma Coptidis, Cortex Phellodendri, Rhizoma Corydalis, Guduchi (Tinospora cordifolia), and Tinospora sagittata roots. Palmatine chloride (PA) is known as an inhibitor of dopamine generation. However, its effect on endoplasmic reticulum (ER) stress-related macrophage activation caused by endotoxin (lipopolysaccharide) is not yet well known. In this study, the effects of PA on pyroptotic responses of mouse macrophages (RAW 264.7) activated by endotoxin were investigated using Griess reagent assay for nitric oxide (NO) production, fluo-4 assay for cytosolic calcium release, dihydrorhodamine 123 assay for hydrogen peroxide production, multiple cytokine assay for cytokine production, real-time PCR for inflammatory gene transcriptions, and flow cytometry assay for p38 MAPK activation. Preliminary experiments using THP-1 human monocytic cells demonstrated that PA was not cytotoxic and significantly reduced basal NO production. Results revealed that PA significantly reduced excessive production levels of NO, hydrogen peroxide, pro-inflammatory cytokines (such as interleukin (IL)-6, CCL3 (MIP-1α), and CSF2 (GM-CSF)), and cytosolic calcium release in endotoxin-stimulated RAW 264.7, but significantly increased the production of anti-inflammatory cytokine IL-10. PA inhibited endotoxin-induced transcripts of Chop, Stat1, Fas, and c-Fos in activated RAW 264.7. It also decreased p38 MAPK phosphorylation and level of Fas in RAW 264.7 stimulated by endotoxin. To further interpret these findings, a network pharmacology-informed analysis based on large-scale literature mining was performed, supporting the multi-target regulatory role of PA in ER stress-related pathways. Briefly, PA exerts anti-inflammatory effects on endotoxin-stimulated RAW 264.7 via the calcium-CHOP pathway, consequently reducing endotoxin-induced production of pro-inflammatory mediators (NO, cytokines, etc.) and relieving ER stress-related pyroptotic cascade. Full article

Ascophyllum nodosum extracts (ANE) are widely used biostimulants associated with improvements in plant growth, productivity, nutrient acquisition, and abiotic stress tolerance. However, the molecular mechanisms linking extract composition to plant signaling and physiological responses remain incompletely resolved. ANE contains a complex mixture of bioactive constituents, including polysaccharides, osmolytes, phenolic compounds, and phytohormone-like molecules. Their composition varies according to biomass source, environmental conditions, and extraction methodology, contributing to variability in biological activity. Current evidence suggests that ANE functions mainly as a signaling modulator rather than a direct nutrient source. ANE treatment has been associated with early cellular responses, including cytosolic Ca²⁺ influx, reactive oxygen species (ROS) generation, and mitogen-activated protein kinase (MAPK)-associated signaling events. However, many proposed mechanisms remain unresolved, and a considerable proportion of the available mechanistic evidence originates from studies using purified ANE-derived polysaccharides or related elicitor systems. ANE-associated responses include modulation of nutrient transport, primary metabolism, hormonal regulation, transcriptional reprogramming, and stress-responsive pathways, contributing to improved root development, nutrient acquisition, and defense-related responses. Nevertheless, limited knowledge of receptor-mediated perception mechanisms, signaling hierarchies, and extract-dependent variability continues to constrain mechanistic understanding and reproducibility. Future research should prioritize receptor identification, bioassay-guided fractionation, integrated multi-omics approaches, and improved standardization of extraction and formulation procedures. These advances will be essential for establishing robust mechanistic models and supporting the development of evidence-based ANE biostimulants for sustainable crop production. Full article

Cross-presentation of exogenous antigens by dendritic cells (DCs) relies on the cytosolic pathway, enabling proteasomal processing and subsequent loading of antigenic peptides onto major histocompatibility complex class I (MHC-I) molecules. Although this pathway is central to CD8⁺ T-cell activation, the molecular mechanisms that regulate intracellular antigen processing and redistribution during cross-presentation remain incompletely defined. In this study, we investigated the contribution of the large-pore channel Pannexin-1 (Panx1) to antigen handling during cross-presentation. Using confocal microscopy and quantitative image analysis in granulocyte–macrophage colony-stimulating factor/interleukin-4 (GM-CSF/IL-4)-derived inflammatory bone marrow-derived dendritic cell (BMDC)-like cellsexposed to ovalbumin (OVA)–Alexa Fluor 488, we observed time-dependent changes in intracellular antigen distribution that were altered upon pharmacological inhibition of Panx1 with the blocking peptide 10Panx1. In parallel, functional assays revealed that Panx1 inhibition significantly reduced SIINFEKL peptide-dependentactivation of B3Z CD8⁺ T-cell hybridomas following pulsing with full-length OVA. Similar effects were observed in the cross-presentation-competent MUTU1940 dendritic cell line. Importantly, Panx1 inhibition did not significantly affect dendritic-cell viability or LPS-induced activation under the experimental conditions tested. In contrast, pharmacological inhibition or genetic deficiency of P2X7 receptor (P2X7) did not produce comparable reductions in cross-presentation, and combined inhibition did not result in additive effects under the experimental conditions tested. Together, these findings provide functional evidence supporting a role for Panx1 in regulating intracellular antigen redistribution associated with cross-presentation. While not establishing direct genetic causality, our data identify Panx1 as a modulatory component influencing antigen-processing events that culminate in CD8⁺ T-cell activation, thereby expanding the current framework of intracellular antigen-processing mechanisms involved in dendritic-cell-mediated cross-presentation. Full article

Background: Autism spectrum disorder (ASD) is associated with immune dysregulation in a subset of individuals, though findings remain heterogeneous and poorly defined, particularly regarding immune subtypes and metabolic context. Methods: We analyzed whole-blood microarray data from GSE18123 (GPL570: ASD n = 46, controls n = 19; GPL6244: ASD n = 68, controls n = 21) using an integrated immunometabolic framework. CD4⁺ T-cell transcriptional programs were used to assign dominant immune phenotypes (TH1, TH2, TH17, Tfh, FOXP3⁺ Treg, Tr1-like). Metabolic demand was quantified via the τ-axis; execution capacity was assessed using cytosolic and mitochondrial energy compensation ratios (CECR, MECR). Induction–execution mismatch was captured by three Gap metrics (Cytosolic, Warburg, Global). Functional validation correlated these metrics with transcriptional signatures of folate transport, one-carbon metabolism, receptor-mediated micronutrient uptake (LRP2–CUBN–AMN), cobalamin processing, and vitamin D activation across both platforms. Results: Six immunometabolic CD4⁺ subtypes were identified within ASD. τ-axis discrimination was strongest for Tr1-like (AUC = 0.811) and Tfh (AUC = 0.825) states, while TH17 profiles were indistinguishable from controls. Despite variation in metabolic demand, CECR and MECR remained relatively preserved, indicating decoupling between induction and execution capacity. Global Gap values were most negative in Tfh and TH1 states and positive in TH17 and controls. Negative Gap states showed coordinated suppression of ATP-intensive micronutrient acquisition pathways, including folate transport (FOLR1/2, SLC19A1), megalin–cubilin-mediated uptake (r ≈ 0.77–0.79), and vitamin D activation (CYP27B1). Intracellular cobalamin processing was upregulated in proportion to metabolic demand (r > 0.9). Findings were directionally replicated across both datasets. Conclusions: These data demonstrate that ASD exhibits structured immunometabolic heterogeneity characterized by subtype-specific demand–capacity imbalance. The Global Gap framework provides transcriptomic evidence of energetic deficit in Tfh- and Tr1-like-dominant states. Future clinical studies should incorporate subtype-stratified assessment of micronutrient status and metabolic execution capacity. Full article

Expression of the mevalonate (MVA) pathway in yeast mitochondria is deployed at commercial scale for production of squalene, because mitochondria contain abundant acetyl-CoA, the starting molecule of the MVA pathway. However, it is still unknown whether this strategy is effective in boosting the post-squalene pathway. Here the potential of this strategy is explored for production of the post-squalene chemical cholesterol, a precursor of many valuable steroidal drugs. A cholesterol-producing yeast strain, named CEN-Cho, was constructed by expressing the biosynthetic genes leading to cholesterol, accompanied by the augmentation of the cytosolic MVA pathway. The CEN-Cho strain produced 60.17 ng/mg fresh weight (FW) of squalene and 121.75 ng/mg FW of cholesterol in shake flask cultivation. When the complete MVA pathway was introduced into the mitochondria of CEN-Cho, yielding CEN-Cho-mMVA, the squalene level was increased to 325.24 ng/mg FW. Unexpectedly, the yield of cholesterol produced by CEN-Cho-mMVA was decreased to 1.5 ng/mg FW, demonstrating significant suppression on the post-squalene pathway due to the mitochondrial engineering. Comparative transcriptomic and proteomic analyses of the engineered cells provide insights into the metabolic and regulatory bottlenecks underlying this inhibition. This work reveals that the introduction of the MVA pathway into mitochondria generally inhibits the post-squalene pathway in yeast. Full article

Background: Allergic rhinitis (AR) is a common inflammatory disorder with an unclear role of lytic cell death (LCD). This study aimed to identify LCD-associated genes associated with AR and investigate their underlying regulatory pathways. Methods: Transcriptomic data from AR patients (GSE19187, GSE206149) were retrieved from public repositories, and LCD-associated genes were collected from the literature. A combination of differential expression analysis, machine learning techniques, validation of expression levels, and ROC curve analysis was employed to screen for biomarkers. These biomarkers were then subjected to comprehensive functional characterization via GSEA, subcellular localization prediction, immune infiltration profiling, construction of molecular regulatory networks, and drug prediction. Finally, clinical relevance was confirmed through expression levels in patient specimens. Results: Two key indicators, ALOX15 and TIMP1, were successfully pinpointed. GSEA revealed significant enrichment of ALOX15 and TIMP1 in several biological processes, specifically chromatin organization, immune system response, and extracellular substance transport. Subcellular distribution studies showed that ALOX15 predominantly localized in the cytosol and plasma membrane, while TIMP1 was mainly detected extracellularly. Immune infiltration studies demonstrated notable modifications in seven immune cell populations, with significant associations with megakaryocyte–erythroid progenitors and conventional dendritic cells. Based on these findings, a regulatory network composed of transcription factors and microRNAs was established, and several potential therapeutic candidates (e.g., quercetin) were identified through prediction. Consistent with predictions, mRNA expression levels of both genes were significantly upregulated in the AR group compared to controls (p < 0.01), confirming reliability. Conclusions: In summary, ALOX15 and TIMP1 were identified as exploratory biomarkers associated with AR, providing preliminary insights into its molecular mechanisms and potential therapeutic implications. Full article