Search Results (835)

Background: Phosphatidylinositol 3-kinase (PI3K) is a promising anticancer drug target, and selective PI3Kα inhibition may provide both efficacy and an improved safety profile. This study aimed to design new potentially selective PI3Kα inhibitors using computer-aided drug design (CADD). Methods: Benzoxazepine and thiazole derivatives were investigated using molecular dynamics, ensemble docking, and Three-Dimensional Quantitative Structure–Activity Relationship (3D-QSAR) analyses. Scaffold hopping, substituent replacement, structure-based virtual screening, and density functional theory (DFT) calculations were then applied to guide the design and characterization of new derivatives. Results: The study identified new chemotypes capable of interacting with PI3Kα Val851 (αVal851) in the hinge region, including chromeno[3,4-d]imidazole, 2H-benzo[b]oxazine, and quinoline derivatives. Additional substructures directed toward hydrophobic region II and the αGln859 interaction environment supported predicted selectivity over PI3Kβ, PI3Kγ, and PI3Kδ. Conclusions: The results establish a comprehensive CADD framework for the rational design of selective PI3Kα inhibitors and provide new compounds with improved predicted selectivity profiles for further development. Full article

Chronic respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis, and chronic bronchitis, are characterized by persistent airway inflammation and mucus hypersecretion, leading to airway remodeling and progressive pulmonary dysfunction. Although current therapies improve disease control, they often fail to adequately target the complex molecular mechanisms underlying chronic airway diseases and may cause adverse effects during long-term use. Natural products have therefore emerged as promising multitarget therapeutic agents because they simultaneously regulate oxidative stress, inflammatory signaling, epithelial dysfunction, and mucus production. Recent evidence demonstrates that marine-derived bioactive compounds and plant-derived phytochemicals modulate key signaling pathways, including nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), Janus kinase/signal transducer and activator of transcription (JAK/STAT), the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, and nuclear factor erythroid 2-related factor 2 (Nrf2), thereby suppressing airway inflammation, oxidative stress, goblet cell differentiation, and MUC5AC overexpression. Advances in nanoformulation, pulmonary drug delivery, multi-omics, artificial intelligence-assisted drug discovery, and network pharmacology are expected to accelerate clinical translation. Collectively, natural products represent promising candidates for the development of evidence-based functional foods, nutraceuticals, and novel therapeutic strategies for chronic respiratory diseases. Full article

Phosphatidylinositol 5-phosphate 4-kinase type 2 alpha (PIP4K2A) is a key oncogenic driver that regulates the PI5P/PIP2 axis to promote metastatic migration in breast cancer. This study aimed to investigate the therapeutic potential of a crude extract from Tamarix aphylla against breast cancer progression and identify its primary active constituents. The crude extract was initially evaluated against MDA-MB-231 and MCF7 breast cancer cell lines using wound healing assays. Bioassay-guided isolation and screening were deployed to isolate individual components, and the most potent lead compound was structurally characterized using preparative HPLC and FTIR. To analyze its interaction with PIP4K2A, in silico molecular docking, MM/GBSA calculations, and 200 ns molecular dynamics simulations were conducted. In vitro validation was subsequently performed via dose-dependent cytotoxicity assays, scratch assays, single-cell tracking, and RT-qPCR expression analysis. Quercetin was identified as the most potent lead inhibitor against PIP4K2A. Computational modeling revealed that quercetin binds tightly within the PIP4K2A ATP-binding pocket, yielding a superior binding affinity of −10.77 kcal/mol and enhanced thermodynamic stability (ΔGMM/GBSA = −42.6 ± 2.1 kcal/mol) compared to the native ligand (ΔG MM/GBSA = −23.3 ± 1.8 kcal/mol). Molecular dynamics simulations confirmed an induced-fit structural transition that locked the complex into an ultra-stable conformation within a deep global energy minimum basin (−10.8 kcal/mol). In vitro assays demonstrated dose-dependent cytotoxicity, with aggressive triple-negative MDA-MB-231 cells exhibiting higher sensitivity (IC₅₀ = 82.23 µg/mL) than luminal MCF7 cells (IC₅₀ = 97.14 µg/mL). Furthermore, scratch and single-cell tracking assays showed a profound suppression of migration speed and wound closure (reduced to ~40%), while RT-qPCR revealed a near-complete transcriptional knockdown of PIP4K2A mRNA expression (down to 0.025-fold). Collectively, these findings elucidate a unique dual-action mechanism for Tamarix aphylla-derived quercetin—characterized by both direct competitive enzymatic inhibition and downstream transcriptional silencing—positioning it as a promising therapeutic scaffold for targeted anti-metastatic breast cancer interventions. Full article

The high-pathogenicity island (HPI) is a major virulence determinant in pathogenic Escherichia coli (E. coli), contributing to severe inflammation and tissue damage. Autophagy plays a critical role in clearing intracellular pathogens and modulating inflammation, but whether HPI manipulates this process remains unknown. Here, using a swine-pathogenic E. coli strain and its HPI-deficient mutant (Δirp2) generated by CRISPR/Cas9, we investigated the interplay between HPI and autophagy in RAW264.7 macrophages and a mouse intestinal infection model. We found that HPI⁺ infection induced autophagic activation, as evidenced by increased LC3 puncta (immunofluorescence), upregulated Beclin-1 and autophagy-related gene mRNA levels (qPCR), and downregulated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) expression at both mRNA (qPCR) and protein (immunohistochemistry) levels. In a mouse model, HPI⁺ infection upregulated intestinal Microfold (M) cell markers and secretory Immunoglobulin A (IgA), triggered robust production of pro-inflammatory cytokines, and induced more severe tissue pathology than the HPI-deficient mutant. Pharmacological activation of autophagy with rapamycin alleviated HPI-induced inflammation and injury, whereas inhibition of autophagy by 3-methyladenine (3-MA) or Beclin-1 silencing exacerbated damage. These findings suggest that HPI induces autophagy, but the endogenous autophagic response is insufficient to counteract HPI-induced pathology; pharmacological enhancement of autophagy partially alleviated this insufficiency and reduced tissue damage. Notably, Beclin-1 knockdown blunted HPI-induced upregulation of PI3K and autophagy-related genes, suggesting a role for Beclin-1 in the transcriptional regulation of these responses. In conclusion, HPI simultaneously exerts direct pro-inflammatory effects and induces Beclin-1-dependent autophagy. Enhancing this autophagic response pharmacologically, rather than relying on the endogenous level triggered by HPI alone, limits excessive tissue damage. Thus, boosting autophagy may represent a promising therapeutic strategy against HPI-bearing pathogenic E. coli infections. Full article

The review covers research on dual-target antitumor agents over the past five years. One of the targets is histone deacetylases (HDACs), while the second potential target is a protein group located both on the membrane surface (phosphatidylinositol 3-kinase (PI3K), anaplastic lymphoma kinase (ALK), receptor tyrosine kinase (AXL), tyrosine protein kinase (HER2), FMS-like tyrosine kinase (FLT3), and vascular endothelial growth factor receptor (VEGFR2)) and in the nucleus (serine/threonine protein kinase Wee1, DNA methyltransferase (DNMT), dual-specificity phosphatase (CDC25A), an enzyme from the cyclin-dependent kinase family (CDK9), dual-specificity tyrosine-serine/threonine kinase (DYRK2), and BET family proteins (BRD4, BD1, and BD2)). This review presents the results of studies on the inhibitory activity of various HDAC isoforms and other enzymes, as well as in vitro cytotoxicity studies on both neoplastic and healthy cells. It also includes selectivity studies, in vivo experiments (changes in tumor volume in mice) and oral bioavailability assessments. The review also describes the chemical structures of several dual-target agents and identifies the molecular fragments responsible for inhibiting different targets. Based on the studies reviewed in this paper, it can be concluded that some dual inhibitors have superior in vitro cytotoxicity and exhibit selectivity towards some tumor cells compared to monofunctional reference compounds. These findings may be useful for molecular design in the field of polypharmacology, with the aim of developing new dual-target molecules that exhibit improved antitumor activity and selectivity towards neoplastic cells. Full article

Breast cancer remains one of the most prevalent malignancies affecting women worldwide and continues to be a leading cause of cancer-related morbidity and mortality. Patients may present with either localized or advanced disease, with clinical outcomes increasingly influenced by molecular subtype and genetic profile. This review highlights the key genetic factors involved in breast cancer, current diagnostic and therapeutic strategies, and promising emerging approaches that may shape future clinical management. Breast cancer diagnosis typically involves clinical breast examination, imaging techniques such as mammography and ultrasound, and confirmatory biopsies. Genetic mutations in specific genes are strongly linked to the development, progression, and metastasis of the disease. Treatment options for localized breast cancer continue to include surgery (lumpectomy or mastectomy) and radiotherapy, combined with systemic therapies tailored to tumor biology, such as endocrine therapy, human epidermal growth factor receptor 2 (HER2)-targeted therapy, and cyclin-dependent kinase (CDK)4/6 inhibitors. For advanced or metastatic breast cancer, recent therapeutic advances include the use of immunotherapy (e.g., immune checkpoint inhibitors), Poly (ADP-ribose) polymerase (PARP) inhibitors for Breast Cancer gene (BRCA)-mutated cancers, antibody–drug conjugates, and novel targeted agents, which have significantly improved patient outcomes in selected populations. Recent findings in breast cancer genetics have highlighted the critical role of germline and somatic mutations, particularly in genes such as BRCA1, BRCA2, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and TP53, in driving tumor initiation, progression, and therapeutic response. Molecular profiling and next-generation sequencing technologies have enabled more precise tumor classification and facilitated the development of personalized treatment strategies. Despite these advances, treatment resistance and disease recurrence remain major challenges, particularly in aggressive subtypes such as triple-negative breast cancer. Consequently, ongoing research is exploring alternative and complementary approaches, including nanotechnology-based drug delivery systems, gene editing techniques such as clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR-associated protein 9) (CRISPR-Cas9), cancer vaccines, and the integration of traditional and plant-derived compounds. These strategies aim to enhance therapeutic efficacy, reduce systemic toxicity, and overcome resistance mechanisms. Full article

Modulating the immune microenvironment has become an emerging strategy for promoting functional bone regeneration, identifying key therapeutic targets remains challenging. Our previous work showed that Nucleotide-binding oligomerization domain-like receptor family caspase recruitment domain containing protein 5 (NLRC5) is involved in bone destruction associated with periodontitis, but its potential and mechanism in regulating bone tissue repair and regeneration have not been fully elucidated. A monocortical bone defect model was established in the mouse femur to assess the impact of NLRC5 on in situ bone healing and regeneration. Mouse bone marrow-derived mesenchymal stem cells (BMSCs) were isolated to evaluate the effects of NLRC5 on osteogenic differentiation, proliferation, and migration. RNA sequencing was used to explore the direct regulatory mechanism of NLRC5 on osteogenic differentiation of mouse BMSCs. Mass cytometry was employed to examine the effect of NLRC5 on the bone marrow immune microenvironment, followed by in vitro validation experiments. Loss of NLRC5 impaired the healing and regeneration of femoral bone defects in mice, and led to a high inflammatory state in the early stage of healing. The absence of NLRC5 inhibited the osteogenic differentiation ability of BMSCs, and could be restored by NLRC5 overexpression, which was achieved through activation of the phosphatidylinositol 3-kinase/protein kinase B(PI3K/AKT) signaling pathway. Mass cytometry data revealed that NLRC5 may serve as an important factor in maintaining the differentiation and maturation of regulatory T cells (Tregs). By modulating the levels of inflammatory cytokines, NLRC5 further influences the osteogenic differentiation of BMSCs. NLRC5 serves as a key regulator and promising candidate for bone repair. NLRC5 contributes to bone regeneration through a dual mechanism: it promotes BMSCs osteogenic differentiation, at least in part via the PI3K/AKT/β-catenin signaling pathway, and indirectly modulates the local immune microenvironment to facilitate bone repair. Full article

Salvia guaranitica A.St.-Hil. Ex Benth. (Lamiaceae) is native from South America, traditionally used for releasing tension and treating gastrointestinal cramps. It was evaluated for the presence of flavonoids and isoflavones in the extract, and the hypothesis of being cardioprotective under ischemia and reperfusion (I/R), antidiarrheal, antispasmodic and anxyolitic in respective models. For phytochemistry, GC-MS and HPLC-DAD methodologies were used. Cardiac performance after subchronic oral administration of S. guaranitica tincture (S.g-T, 0.95 mg extract/mL) was evaluated in rat isolated perfused hearts exposed to I/R, and mechanisms were characterized. Antispasmodic effects of S.g-T were evaluated on contractile concentration–response curves (CRCs) of carbachol (CCh) and calcium (Ca²⁺) in rat isolated intestinal tissue. In vivo tests of ricin-oil diarrhea models, open-field (OFT), novel-suppressed feeding (NFT) and tail suspension (TST) tests were performed on mice. Phenolic acids, genistin, luteolin, kaempferol and quercetin glycosides, genins, loliolide, dodecane, farnesene, phytol and isochiapin B were identified. Post-ischemic cardiac recovery was improved by S.g.-T, associated to activation of phosphatidylinositol-3-kinase and β-estrogenic receptor. S.g.-T also induced antispasmodic effects, as a non-competitive inhibitor of the CCh-CRC and Ca²⁺-CRC in the intestine. In vivo, S.g.-T showed antidiarrheal activity (95 mg extract/kg) and anxiolytic-like effects (0.95–9.5 mg extract/kg) without sedation or antidepressant-like effects. Therefore, S. guaranitica leaves have potential therapeutic cardioprotective, antidiarrheal, antispasmodic and anxiolytic effects. Full article

Emerging evidence links gut microbiota (GM) dysbiosis to hyperuricemia (HUA). The GM plays a critical role in regulating host health and homeostasis by producing a diverse array of metabolites, including short-chain fatty acids, bile acids and uremic toxins. Dysregulation of the microbial metabolite profile has been implicated in the pathogenesis of HUA. Given the urgent need for green and safe urate-lowering therapies for HUA, recent years have seen an increasing focus on interpreting the ability of natural products to modulate these microbial metabolites. Such interventions enhance beneficial metabolites and suppress uremic toxins, thereby alleviating HUA through coordinated regulation of urate transporters, restoration of intestinal barrier integrity, reprogramming of systemic metabolic disturbances, and inhibition of inflammation via Toll-like receptor 4 (TLR4)/ nuclear factor kappa B (NF-κB), Janus kinase (JAK)/ signal transducer and activator of transcription (STAT), and Phosphatidylinositol-3-kinase (PI3K)/ protein kinase B (AKT) pathways. Furthermore, a comprehensive translational roadmap has been proposed, grounded in a critical appraisal of current trial limitations. Overall, this review consolidates evidence for the protective effects of natural products against HUA and related comorbidities, with an emphasis on GM-derived metabolites, aiming to expand clinical applications and provide insights for future studies. Full article

Tau protein aggregation and spreading are central features of neurodegenerative diseases such as Alzheimer’s disease and frontotemporal dementia. Here, we investigated the role of phosphatidylinositol 4-kinase type IIIα (PI4KIIIα) in regulating tau propagation. We first used tau biosensor cells to demonstrate that both pharmacological inhibition and genetic reduction in PI4KIIIα effectively reduce the seeding of tau aggregation by extracellular seeds. To extend these findings to a more physiologically relevant system, we generated induced pluripotent stem (iPS) cell-derived cortical neurons carrying pathogenic MAPT mutations. These neurons rapidly acquired tauopathy-associated features, including expression of disease-relevant isoforms such as 4R tau, thereby enabling in vitro modeling of tau pathology. Using this model, we established phenotypic assays to monitor tau propagation and aggregation and applied them to test candidate small molecules. Notably, inhibition of PI4KIIIα consistently reduced seeding of tau assemblies in human neurons, highlighting this kinase as an important player in the seeding of tau pathology. Collectively, our work identifies PI4KIIIα as a regulator of tau pathology and provides new experimental platforms to dissect the molecular mechanisms of tau propagation. These findings open potential avenues for the development of strategies to slow or prevent tau-mediated neurodegeneration in the central nervous system. Full article

Total RNA was isolated from sections of healthy testes and Leydig cell tumors of mixed-breed dogs using TMA Master II device. The RNA-seq libraries were sequenced on the Illumina platform. Following differential expression analysis, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were applied with quality control obtained using FastQC and Trimmomatic. This analysis revealed 1500 transcripts, including 982 upregulated and 168 downregulated genes. The results demonstrated that a significant proportion of these differentially expressed genes are directly involved in the control of sex steroid production (CYP11A1, STAR, and 3β-HSD3B1) or tube formation, angiogenesis, and extracellular matrix remodeling in interstitial cells (ESM1, FGG, and VEGFA). Moreover, we identified the upregulation of transcripts responsible for neurotransmitter or neuroendocrine signaling (SLC6A4, GRIN2C, GABRB3) and cholesterol metabolism and its regulation (GPX3, MSMO1, DHCR24). These genes were strongly associated with the phosphatidylinositol-3-kinase (PI3K)-Protein Kinase B (Akt) cascade and extracellular matrix interactions, features shared with various malignancies. Alterations in estrogen and relaxin signaling appear to be distinctive, understudied mechanisms specific to canine Leydig cell tumors. Concurrently, downregulated genes (e.g., DMRTC2, SEMA3C, ALOX12) were linked with cell differentiation, signaling and immunoregulatory pathway suppression involved in tumorigenesis. A complex transcriptomic profile of canine Leydig cell tumors was developed, revealing a conserved oncogenic core shared in some aspects with human malignancies alongside unique species-specific alterations. Findings seem to be useful for identifying novel diagnostic biomarkers and targeted therapies in veterinary oncology, establishing canine reproductive tissues as a valuable comparative biomedical model for research in human. Full article

As a traditional element of Chinese medicine, Hippocampus erectus is well known for promoting adolescent growth, yet its active fractions and underlying molecular mechanisms remain unclear. In this study, the aqueous extract of H. erectus was subjected to in vitro simulated gastrointestinal digestion and ultrafiltration to separate three molecular weight fractions (<10 kDa, 10–30 kDa, >30 kDa). Their chemical profiles were characterized, and osteogenic activities were systematically evaluated using cell assays, a juvenile rat model, and integrated transcriptomics and data-independent acquisition (DIA) proteomics. Results revealed that chemical profiling showed the >30 kDa fraction was mainly composed of hemocyanin subunits, and the 10–30 kDa fraction was enriched in growth-related amino acids and steroid derivatives; functionally, the 10–30 kDa fraction promoted preosteoblast proliferation and early differentiation via enhanced alkaline phosphatase (ALP) activity, while the >30 kDa fraction dominated late osteoblast maturation and mineralization. Both fractions significantly increased rat body and bone length by expanding growth plate proliferative zones and elevating serum insulin-like growth factor-1 (IGF-1)/bone morphogenetic protein-2 (BMP-2) levels. Transcriptomic and proteomic analyses identified vascular endothelial growth factor (VEGF), Wingless-related integration site (Wnt), phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt), and extracellular matrix (ECM)–receptor interaction as potential core regulatory pathways. Integrated multi-omics analysis further confirmed Frizzled-related protein B (Frzb) and AKT1 substrate 1 (Akt1s1) as candidate key regulatory targets enriched in the Wnt and adenosine monophosphate-activated protein kinase (AMPK) signaling pathways. These findings elucidate the multi-fraction, multi-pathway mechanism of H. erectus in promoting skeletal development, providing scientific evidence for its traditional use and a theoretical basis for growth-promoting functional food development. Full article

Inflammatory bowel disease (IBD) poses a significant global health burden with rising incidence, particularly in Asia. This study employed an integrative network pharmacology approach combined with molecular docking to elucidate the therapeutic mechanism of ganoderic acid A (GAA) against IBD. Potential GAA targets were retrieved from pharmacogenomic databases, while IBD-related genes were curated from OMIM and GeneCards databases. Weighted gene co-expression network analysis of IBD transcriptomic datasets (GSE38713, GSE126124) identified disease-associated modules, with the yellow module exhibiting the strongest positive correlation. Functional enrichment analyses demonstrated significant involvement of overlapping targets in lipid metabolism, the inflammatory response, and the mitogen-activated protein kinase (MAPK) signaling cascade pathway. We identified 14 IBD-GAA-ferroptosis-related genes and 54 key module genes. Intersection analysis revealed 5 overlapping targets, including tumor necrosis factor-α(TNF-α), peroxisome proliferators-activated receptor γ (PPARγ), MAPK14, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic α (PIK3CA), and Caspase 3 (CASP3). Molecular docking confirmed high-affinity binding of GAA to these targets, with binding energies ranging from −7.3 to −10 kcal/mol. Crucially, experimental evaluation demonstrated the pivotal role of GAA in alleviating disease pathology. GAA treatment suppressed the significantly elevated levels of TNF-α and p-MAPK14 in the organoids using a cytokine/LPS-induced IBD model. These findings collectively suggest a potential involvement of GAA in pathways associated with ferroptosis regulation, although direct experimental evidence for ferroptosis markers remains to be established. The observed multi-target effects on immune regulation and cellular proliferation/differentiation provide a foundation for further mechanistic investigation. Full article

Liancheng white ducks have a distinctive “white feathers, black beak, and green feet” phenotype, making them a useful model for studying pigmentation traits in waterfowl. The previous study found that the F1 generation of Liancheng white ducks crossed with white-feathered ducks and hemp-feathered ducks were all gray-black in color. This indicates the specificity and complexity of melanin deposition in Liancheng white ducks, which makes the selection and breeding of pigment traits through phenotyping difficult. The aim of this study was to investigate the candidate transcriptomic regulatory signals of melanogenesis in Liancheng white ducks. Skin, mouth skin, foot skin, liver, and muscle samples were collected from 130-day-old Liancheng white ducks. Morphological differences were observed via histological analysis, and extraction-based pigment levels were determined. The results showed that melanin granules were clearly observed in tissues other than the liver and were distributed mainly in the basal layer of the epidermis and around feather follicles; the pigment values in the tissues decreased in the order mouth skin > liver > foot skin > muscle and skin. However, the relatively high liver value should be interpreted cautiously because obvious melanin granule deposition was not observed histologically. Whole-transcriptome sequencing was performed on mouth skin and skin samples. In total, 3074 differentially expressed genes (DEGs) were screened; upregulated genes associated with melanogenesis included melanocyte inducing transcription factor (MITF) and tyrosinase (TYR); downregulated genes included agouti signaling protein (ASIP) and adenylate cyclase 2 (ADCY2). Eighteen differentially expressed microRNAs (DEmiRNAs) were identified. Based on target prediction and pathway enrichment analysis, novel_290 and apl-miR-11588-3p were identified as candidate miRNAs potentially associated with melanogenesis-related pathways, and their predicted target genes included phosphatidylinositol 3-kinase (PI3K) and Janus kinase 1 (JAK1). Additionally, 364 differentially expressed long noncoding RNAs (DElncRNAs) were identified; TCONS_00063335 and TCONS_00019814 were identified as candidate lncRNAs potentially associated with melanogenesis-related genes, including TYR and TYRP1. A putative ceRNA network was constructed based on the predicted miRNA–mRNA and miRNA–lncRNA relationships, and ENSAPLT00000025522–apl-miR-11588-3p–MAPK8IP3 was identified as a candidate network relationship associated with MAPK-related pigmentation pathways. However, because this relationship was inferred mainly from bioinformatic prediction and expression association analysis, further functional validation is required to confirm whether it contributes to melanogenesis regulation. These findings provide candidate transcriptomic and noncoding RNA information for the further investigation of tissue-specific pigmentation in Liancheng white ducks. Full article

Carbon monoxide (CO) is a gasotransmitter generated by heme oxygenase (HO) isoforms during heme catabolism. The inducible HO-1 produces CO under conditions of redox imbalance, such as oxidative stress and inflammation. On the other hand, HO-2 constitutively generates CO, primarily during the physiological turnover of heme. Extensive evidence indicates that CO exerts autocrine effects by targeting hemoproteins, including soluble guanylyl cyclase, cyclooxygenase, and cytochromes. Furthermore, CO regulates many biological processes within the brain, including mitochondrial biogenesis, potassium channel activity, mitogen-activated protein kinase and phosphatidylinositol-3-kinase/Akt signaling. It also controls the activity of transcription factors, such as hypoxia-inducible factor-1 and peroxisome proliferator-activated receptor-γ. Through these mechanisms, CO modulates inflammatory gene expression, promotes anti-apoptotic signaling, and contributes to local stress responses. Conversely, CO produced in the hypothalamus inhibits the stress-induced release of corticotropin-releasing hormone and arginine vasopressin under pro-inflammatory conditions, resulting in reduced adrenocorticotropin hormone release and cortisol secretion from the anterior pituitary and adrenal cortex, respectively. Moreover, hypothalamic CO acts in a paracrine manner to modulate glucocorticoid release during psychological stress, including restraint or water deprivation. Together, these findings support the view that endogenous CO is a key modulator of the stress axis, exerting pleiotropic effects that integrate neuroendocrine, immune, and metabolic responses. Full article